Field
This disclosure relates generally to an augmented reality sound system. In particular, this disclosure relates to augmenting ambient sound in an environment so as to add elements to ambient sound so as to emphasize or deemphasize particular characteristics of the ambient sound or to provide additional detail regarding the ambient sound or surroundings in addition to the ambient sound.
Description of the Related Art
Humans' perception to sound varies with both frequency and sound pressure level (SPL). For example, humans do not perceive low and high frequency sounds as well as they perceive midrange frequencies sounds (e.g., 500 Hz to 6,000 Hz). Further, human hearing is more responsive to sound at high frequencies compared to low frequencies.
There are many situations where a listener may desire emphasis or de-emphasis of ambient sound at certain frequencies, while allowing ambient sound at other frequencies to reach their ears. For example, during a riot, police or military personnel may wish to maintain typical ambient sounds without impeding hearing (for example, with an in-ear earbud for communications with group members) while enabling emphasis on particular types of sounds, such as gunshots or footsteps. Similarly, directionality of sound may be desirable so as to alert group members of dangerous locations or to better pinpoint danger.
Still further, superimposing augmented sound over ambient sound may be desirable in situations in which blocking out all or most ambient sound in order to provide additional direction or information in the audio may be dangerous. Removing ambient sound from one ear significantly reduces the human capability to determine the direction from which sound emanates. So, if the target of a police raid yells or takes a step, but one of a police officer's ears is filled with a small speaker, the officer may have only a vague idea of the direction from which the yell or step came.
In contrast, there are many situations in which additional sounds superimposed over ambient sound or in addition to ambient sound may be helpful. For example, individual, directions guiding an individual to a location or guiding an individual within a building or enclosed space may be useful. However, such direction or guidance may put the individual in harms way by either blocking out ambient sound through the use of a small in-ear speaker or by broadcasting the directions (and location) to anyone within earshot when using an out-of-ear speaker. Thus, reproducing the ambient sound with the directions superimposed over the ambient sound is preferable to either, more dangerous option. These and other uses of augmented reality for ambient sounds are discussed below.
Throughout this description, elements appearing in figures are assigned three-digit reference designators, where the most significant digit is the figure number where the element is introduced and the two least significant digits are specific to the element. An element not described in conjunction with a figure has the same characteristics and function as a previously-described element having the same reference designator.